Premium
An auditory brainstem nucleus as a model system for neuronal metabolic demands
Author(s) -
Brosel Sonja,
Grothe Benedikt,
Kunz Lars
Publication year - 2018
Publication title -
european journal of neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.346
H-Index - 206
eISSN - 1460-9568
pISSN - 0953-816X
DOI - 10.1111/ejn.13789
Subject(s) - brainstem , neuroscience , premovement neuronal activity , neuron , hippocampal formation , biology , electrophysiology , nucleus , stimulation , biophysics , chemistry , biochemistry
The correlation between neuronal activity and metabolism is essential for coding, plasticity, neurological disorders and the interpretation of functional neuroimaging data. Most likely, metabolic requirements depend upon neuron type, and macroscopic energy demands vary with brain region. However, specific needs of individual neuron types are enigmatic. Therefore, we monitored metabolic activity in the lateral superior olive ( LSO ), an auditory brainstem nucleus containing only one neuron type. LSO neurons exhibit extreme but well‐described biophysics with firing rates of several hundred hertz and low input resistances of a few megaohms. We recorded changes in NADH and flavin adenine dinucleotide ( FAD ) autofluorescence and O 2 concentration in acute brainstem slices of Mongolian gerbils ( Meriones unguiculatus ) following electrical stimulation. The LSO shows the typical biphasic NADH / FAD response up to a physiologically relevant frequency of 400 Hz. In the same animal, we compared the LSO with the hippocampal CA 1 region and the cerebral cortex. The rate of NADH / FADH 2 consumption and regeneration was slowest in LSO . However, frequency dependence was only similar during the consumption phase but varied during regeneration within the three brain regions. Changes in NADH , FAD and O 2 levels and blocking metabolic reactions indicate a pronounced contribution of mitochondrial oxidative phosphorylation in the LSO which is known for the other brain regions as well. Lactate transport and interconversion are involved in LSO metabolism as we found in immunohistochemical and pharmacological experiments. Our findings show that the LSO represents an apt, biophysically distinct model for brain metabolism and that neuronal properties determine metabolic needs.